Robert Frank utilizes deep depth of field in this image because of the diversity of the environment around him. He wanted to capture all of the different people in the train windows to show the diversity of America & truly capture the sense of America being the “melting pot”. In Frank’s book The Americans, he utilized this image in a sequence to give greater context to his photos with shallow depth of field.
For instance, this image has a shallower depth of field, which naturally means it’s lacking a bit of context. It isolates the subject, which in my opinion really elevates this photo’s storytelling. However, if put in a bubble by itself, the photo loses some of that storytelling strength, as there’s not much indication to the time period or the setting besides what the viewer can infer from the abstract background & the subject’s car & clothing. However, when sequenced alongside a photo with a deep depth of field (such as the photo above), it brings the photo the elements it was missing in the first place; now, the image isn’t just a visually stunning photo, it also tells a more fleshed out story due to the added detail of the deep depth of field image.
In the top image, background details are sharp in contrast to the bottom image. Good selection.